The presumptive Republican presidential nominee also asked voters to support him in Tuesday's primary and requested their "help for Nov. 6" -- Election Day. Former Pennsylvania Sen. Rick Santorum dropped out of the race this month, leaving Romney with no serious opposition in the primary.
Romney campaigned Monday at Consol Energy, a Fortune 500 natural gas company based in Pittsburgh. Romney said Obama has put the U.S. on a road where "energy is going to become more and more expensive."
Romney also planned an afternoon stop in Aston, Pa., with Florida Sen. Marco Rubio. The Cuban American often is mentioned as a possible running mate for Romney.